Good day, With the outstanding assistance of the TP-Link support team, I was able to make it work. Do not disable DHCP or Mobile WAN NAT on NE200. With the above still ON, enable IP Passthrough,...

@David-TP Thanks, David!

@David-TP Hello, David. Thanks for the quick spot on and reply. Currently, NE200 is in the test environment (inside), do not care about signal strength. Screenshot with IP Passthrough configuration...

It seems NE200 Firmware doesn't really support clean bridge mode (via IP Passthrough). I wish EN200 to work in bridge mode to provide internet directly to my Omada ER605 gateway WAN1 port. I enabled...